Service manual

EPSON LX-300+ Revision A
Operating Principles Printer Mechanism (M-3M10) 49
COLOR MECHANISM INITIALIZATION
The printer mechanism initializes when the power is applied or when
recovering from the energy saving mode.

Color mechanism initialization
Color mechanism initialization shifts color mechanism for the black
ink area to be at the home position. Color mechanism initialization
shifts the carriage at the same time to prevent the ribbon from
hanging on the printhead.
When the buffer is cleared or when the printer is under the pause
condition, the color mechanism initializes and waits for the next
printing command.
2.2.4 Platen Gap Adjustment Mechanism
This mechanism is to adjust the distance between the platen and the
printhead (platen gap) according to the paper thickness.
The following is the components of the LX-300+ platen gap adjustment
mechanism and its explanation. (Refer to Figure 2-5, "Platen Gap Adjustment
Mechanism")
 Carriage: Mounts the printhead.
 Carriage guide shaft: Shifts the carriage horizontally.
 Adjust lever and Parallelism adjust bushing:
Installed at the both ends of the carriage guide shaft
 Platen gap detector (PG_SW)
Carriage guide shaft is eccentric toward the adjust lever rotating center. Due
to this, when rotating the adjustment lever back and forth, the printhead shifts
toward and against the platen to adjust the platen gap. When printing on thick
paper such as postcards and envelops, set the adjust lever over the 1st level.
PG detector shifts the printer to the copy mode from the printing mode.
Printing speed will be lowered but it prevents wire from breaking off.
PLATEN GAP (PG_SW) DETECTOR
The following is PG_SW specification.
Figure 2-5. Platen Gap Adjustment Mechanism
Table 2-9. PG_SW Detector Specifications
Item Specification
Method Mechanical contact method
Switching rate 0.6 to 1.0 mA, 5 VD±5%
Switching mode
•PG=0: close
• PG=0-4: open
Adjust lever
Carriage guide shaft
Carriage
Parallelism adjust
bushing
Printer mechanism
Parallelism adjust
bushing
PG_SW
Platen gap
Platen
Carriage guide shaft
Carriage
Printhead
Adjust lever